植物蔗糖合酶的结构、功能及应用

蔗糖合酶（Sucrose synthase, EC 2.4.1.13, SuS）是植物中广泛存在的一种糖基转移酶，能催化蔗糖的分解及合成反应，是叶片光合作用产物蔗糖进入各种代谢途径所必需的关键酶之一，在植物的生长发育过程中发挥着至关重要的作用．近年研究表明，蔗糖合酶不仅在植物淀粉合成、提高植株抗逆性和影响植株生长等方面扮演着重要的角色，也能为机体提供核苷单糖供体，而这个特性也使得蔗糖合酶基因可以作为一个催化成分被用于核苷单糖的生物合成，具有广泛的应用前景．本文对蔗糖合酶家族基因的染色体定位及功能、蔗糖合酶的结构及亚细胞定位，以及其所具有的生物学功能进行了综述，旨在为蔗糖合酶的进一步研究奠定理论基础．

Gene Organization,Function and Application of Plant Sucrose Synthase

Sucrose synthase(SuS, EC 2.4.1.13 ), a member of the glycosyltransferase family of enzymes, are ubiquitous in the plant kingdom and catalyzes in vivo and vitro the synthesis and cleavage of sucrose. Sucrose synthase is one of the key enzymes in the plant carbohydrate metabolism and regulates the assignment of sucrose, a kind of products of photosynthesis, into a variety of plant metabolic processes. Sucrose synthase also plays pivotal roles during plant growth and development. Previous studies have been demonstrated that sucrose synthase functions in various biological processes, including providing a substrate for starch synthesis in storage organs of plants, promoting plant stress-resistance and regulating plant growth and development. Additionally, sucrose synthase provides nucleotide sugars as precursors for starch and cellulose biosynthesis, which makes it a versatile biocatalyst for the synthesis of nucleotide sugars and related activated glycosides. This review, therefore, covers the recent developments related to the chromosome location of sucrose synthase genes, the method of functional identification, structure and subcellular localization of the enzyme, and its biological functions. These results provide a synopsis of a more global view of sucrose synthase than those previously available.